The present disclosure is directed to monitoring and treating heart arrhythmias with the administration of electrical therapy and to an energy delivery apparatus for imparting the electrical therapy.
A wide variety of electronic and mechanical devices monitor and treat medical conditions. In some examples, depending on the underlying medical condition being monitored or treated, medical devices such as cardiac monitors or defibrillators may be surgically implanted or externally connected to a patient. In some cases, physicians may use medical devices alone or in combination with drug therapies to treat conditions such as cardiac arrhythmias.
One of the most deadly cardiac arrhythmias is ventricular fibrillation, which occurs when normal, regular electrical impulses are replaced by irregular and rapid impulses, causing the heart muscle to stop normal contractions. Normal blood flow ceases, and organ damage or death can result in minutes if normal heart contractions are not restored. Because the victim has no perceptible warning of the impending fibrillation, death often occurs before medical assistance can arrive. Other cardiac arrhythmias can include excessively slow heart rates known as bradycardia or excessively fast heart rates known as tachycardia. Cardiac arrest can occur when the heart experiences various arrhythmias that result in the heart providing insufficient levels of blood flow to the brain and other vital organs for the support of life. Such arrhythmias include, for example, ventricular fibrillation, ventricular tachycardia, pulseless electrical activity (PEA), and asystole (heart stops all electrical activity).
Cardiac arrest and other cardiac health ailments are a major cause of death worldwide. Various resuscitation efforts aim to maintain the body's circulatory and respiratory systems during cardiac arrest in an attempt to save the life of the patient. The sooner these resuscitation efforts begin, the better the patient's chances of survival. Implantable cardioverter/defibrillators (ICDs) or external defibrillators (such as manual defibrillators or automated external defibrillators (AEDs)) have significantly improved the ability to treat these otherwise life-threatening conditions. Such devices operate by applying corrective electrical pulses directly to the patient's heart. Ventricular fibrillation or ventricular tachycardia can be treated by an implanted or external defibrillator, for example, by providing a therapeutic shock to the heart in an attempt to restore normal rhythm. To treat conditions such as bradycardia, an implanted or external pacing device can provide pacing stimuli to the patient's heart until intrinsic cardiac electrical activity returns.
Example external cardiac monitoring and/or treatment devices include cardiac monitors, the ZOLL LifeVest® wearable cardioverter defibrillator available from ZOLL Medical Corporation, and the AED Plus also available from ZOLL Medical Corporation.
External pacemakers, defibrillators and other medical monitors designed for ambulatory and/or long-term use have further improved the ability to timely detect and treat life-threatening conditions. For example, certain medical devices operate by continuously or substantially continuously monitoring the patient's heart through one or more sensing electrodes for treatable arrhythmias and, when such is detected, the device applies corrective electrical pulses directly to the heart through one or more therapy electrodes.